The evening mist clung to Tengen's estate. Tanjiro hesitated at the ornate gates despite the urgency gnawing at his chest.
Three days of sleepless nights had carved shadows beneath his eyes. Three days of watching Akira's perfect smile while his enhanced senses screamed warnings he couldn't articulate.
"Your shoulders carry questions tonight, Kamado."
Tanjiro's hand stilled on the gate latch. Tengen's voice drifted from somewhere beyond the compound walls, casual as morning conversation despite the late hour.
"Tengen-san." Tanjiro straightened, unsurprised by the former Hashira's awareness. "I was hoping we could talk."
"About our new colleague, I'd guess."
The statement hit like a blade between ribs. Tengen emerged from shadows near his gate, moving with surprising quiet despite the walking cane that had replaced his lost arm's balance.
"Come inside before the neighbors start gossiping about mysterious late-night visits."
"How did you—"
"Your footsteps carries worry. And you've been avoiding the common areas at headquarters for three days." Tengen gestured toward his front entrance. "Inside. Some conversations require proper privacy."
---
Following Tengen deeper into his home, Tanjiro noticed how each space flowed into the next with defensive precision. No direct sightlines from outside. Multiple exit routes. Furniture positioned to provide cover rather than comfort.
Even in retirement, Tengen lived like a man expecting ambush.
"Forgive the precautions." Tengen led him into a windowless chamber lined with thick silk hangings. "Old habits from my shinobi days. Sound travels in ways most people don't consider."
A single oil lamp cast wavering shadows across low cushions. The room felt like a war council chamber—which Tanjiro suspected was exactly what Tengen intended.
"This seems excessive for—"
"Is it?" Tengen settled across from him, his remaining eye sharp. "Tell me about your recent missions with Shiranui Akira."
The direct question made Tanjiro's chest tighten. No preamble. No social pleasantries. Just the unvarnished demand for truth between veterans.
---
"What makes you think there's anything to discuss?" Tanjiro asked, though his voice betrayed the relief of finally having someone willing to listen.
"Because you're here instead of celebrating another successful demon purification with your partner." Tengen's voice carried dry humor. "Because your footsteps has carried anxiety for days. And because you've started unconsciously checking exits whenever she enters a room."
Heat flooded Tanjiro's cheeks. "I didn't realize I was being so obvious."
"You're not. Most people wouldn't notice." Tengen leaned forward slightly. "But I spent years reading enemy intentions through body language. Your instincts are trying to tell you something important."
The validation hit harder than expected. Tanjiro had spent three days convincing himself he was imagining problems. Having Tengen treat his concerns as legitimate felt like permission to voice forbidden thoughts.
"I don't want to speak badly of a fellow Hashira," Tanjiro began carefully.
"But?"
"Her scent... it changes." The admission felt like stepping off a cliff. "Sometimes she smells human, sometimes like something else entirely. Not demon, exactly, but not fully human either."
Tengen nodded as if the observation confirmed rather than surprised him. "Go on."
"And the demons we encounter—they don't fight her. They just..." Tanjiro searched for words that wouldn't sound insane. "They go still when she breathes at them. Completely docile. Then they disappear into shadows before I can confirm they're actually dead."
"Her sword?"
"Always clean. No blood, no demon ash." Tanjiro's hands clenched in his lap. "She calls it purification, but I've never seen anything like it. Maybe peace has dulled my senses. Maybe I'm imagining problems where none exist."
"Or maybe," Tengen said quietly, "your instincts are trying to save your life."
---
The words hung heavy as incense. Relief flooded through Tanjiro's chest as he met Tengen's gaze and found no dismissal—only the focused attention of a predator recognizing another predator's warning signals.
"Then I'm not losing my mind."
"Far from it. You're showing the judgment that makes you worthy of the Hashira title." Tengen reached beneath the low table and produced a thick folder. "I've been conducting my own investigation into our mysterious new colleague."
"You have?" The confirmation that his suspicions were shared felt like sunrise after endless night.
"Since the day she arrived. Something about her story didn't add up from the beginning."
Tengen spread documents across the table with practiced efficiency. Official seals caught the lamplight. Tanjiro recognized the Corps' internal paperwork alongside village records and government documents.
"Shiranui Akira. Appeared six months ago claiming independent training in mountain isolation." Tengen's finger traced a timeline written in precise calligraphy. "Self-taught breathing style developed through personal tragedy and determination."
"That's not unusual for some breathing styles—"
"Except there's no record of her existence before that moment." Tengen's voice carried hunter's satisfaction. "No family registry. No birth records. No witnesses to her supposed heroic demon slaying."
Tanjiro leaned forward, studying the papers with growing alarm. Names, dates, locations—all meticulously documented, all pointing toward the same impossible conclusion.
---
"These are official Corps documents," Tanjiro observed, his voice tight with growing dread.
"And village records, census data, merchant registries." Tengen organized the papers. "She's a ghost, Kamado. Someone who didn't exist until she needed to join our ranks."
"But her demonstration for Master Ubuyashiki—the captured demon went completely docile..."
"Was impressive, yes. But impressive isn't the same as legitimate." Tengen pulled out another document bearing a mountain village's seal. "I spoke with village elder Hayato from the settlement she claimed to have saved."
"What did he say?"
"'No demons in these parts for over a year, and certainly no lady swordsman. I'd remember someone like that.'" Tengen quoted. "Direct quote. The man was absolutely certain."
Tanjiro's stomach dropped like a stone into dark water. If Akira had lied about her background, what else had she fabricated?
"She lied about her entire history?"
"It appears so. But that raises the crucial question—why join the Corps under false pretenses?"
Tanjiro grasped for innocent explanations, though each felt increasingly hollow. "Maybe she genuinely wants to help but felt her real background wasn't impressive enough for Hashira consideration?"
---
"That's what I hoped initially." Tengen's expression darkened as he unrolled a detailed regional map marked with colored pins. "Until I started mapping her mission results."
Red dots clustered in certain areas, while blue pins formed patterns that made Tanjiro's enhanced pattern recognition scream warnings.
"Red pins represent confirmed demon activity before her arrival. Blue pins show reported activity after her missions."
Tanjiro studied the map, his heart sinking as the pattern became undeniable. The evidence spread before him like a tactical nightmare, each pin a small betrayal of everything he'd been taught to believe about their mission.
"The demons aren't dying. They're moving."
"Exactly. Activity shifts from her mission areas to adjacent regions within days of her 'purifications.'" Tengen's finger traced the migration patterns with grim satisfaction. "Systematic relocation rather than elimination."
"But why would someone want to relocate demons instead of destroying them?"
The question tasted like poison because his mind was already supplying answers—none of them reassuring. Each possibility led down darker paths than the last, toward conclusions that challenged everything he understood about the Corps' purpose and the nature of their war against demonkind.